Home Diagnosis and TroubleshootingOBD Diagnostic Error Codes P0496 Chevy – EVAP Flow During A Non-Purge Condition (Fixes)

P0496 Chevy – EVAP Flow During A Non-Purge Condition (Fixes)

by Jordan Harris
P0496 Chevy

Have you gotten the check engine and diagnosed a P0496 Chevy? Well, if that is the case, then you are at the right place because, in this article, there will be quite a lot to cover on this topic.

Car problems are inevitable. Especially if you own an older vehicle that is 10+ years old or some beater car. You just cannot avoid them. And in most cases, there are these simple issues like the check engine light and sensor-related problems.

This is the case because cars are fully loaded with these electronic components and as we all know, electronics break down very often. And this is one of the downsides of going fully digital. You just never know what will break down next. So, being always prepared for these problems is the way to go in our opinion.

You just have to be prepared in order to tackle these problems in no time. And by this, we mean that you should know car diagnostics and how it is done on a modern vehicle. Not to mention how much is for a car diagnosis. As well as the tools you will need in order to get this problem sorted out.

And that’s what we are going to cover in the first chapter, where we are going to learn more about car diagnostics. Then we will move on to the problem and see how the EVAP system works and then we will elaborate on the code P0496 Chevy Silverado and see what is the definition, causes, and symptoms, and also how to diagnose it.

Car Diagnostics

Before we dive into more complex topics like the P0496 Chevy Cruze (fun fact, go check out our write-up on the 2013 Chevy Cruze catalytic converter), let’s first introduce ourselves to the topic and learn more about car diagnostics in general. Let’s try to understand more about what car diagnostics are and how this process is done on a modern car.

Modern cars as you probably know are not the same as classic cars. Cars back in the day didn’t have computers, sensors, and other complex electronics. They were plain and simple to diagnose and also to work on.

Modern cars on the other hand are much more complex. They are regulated by the main computer, also known as ECM or PCM (aka the powertrain control module). This control unit basically regulates the work of the sensors, ignition, and other important systems inside your car.

P0496 Chevy

And all these components added complexity. And this had to be standardized for every carmaker out there. After 1996, all carmakers had to comply with the OBD2 standard. So, every modern car has an OBD2 port that allows you to access the computer with the help of an OBD2 scanner.

OBD2 scanners can be simple, they can only read codes. Or they can be very complex and read live data and how a sensor performs. So, you can diagnose a bad component.

Either way, you will also need a tool known as a multimeter. With a multimeter, you can read the electric properties that a component creates. You can bench test or backprobe a sensor and read different properties. Namely, voltage, resistance, and continuity.

The multimeter and the OBD2 scanner are must-have tools if you want to diagnose the P0496 Chevy Traverse code. But how the EVAP system works? Well, let’s find out more about that in the following chapter.

EVAP System

Another topic that we would like to cover before we dive into the problem with the P0496 Chevy is your car’s EVAP system. We need to further understand more about this system and how it works. This is crucial to know since a lot of people are starting to solve the problem without the proper background.

The EVAP system is the Evaporative Emission System. This system was designed to tackle the harmful gases that gasoline is releasing into the atmosphere.

If you didn’t know, gasoline tends to evaporate once poured inside the gas tank. And these harmful vapors then get released into the atmosphere. So, in order to tackle this problem, the EVAP system was invented.

And this is a very smart and simple system. In general, the EVAP system consists of a gas tank, gas cap, lines, charcoal canister, purge valve, and vent valve or the EVAP solenoid. The system goes from the rear to the front of the car.

This is the case because the gases from the gas tank are pushed forward to the charcoal canister. And then from the charcoal canister, the gases are purged into the intake with the help of the purge valve.

The purge valve is purging the gases into the intake, while the vent valve controls the outside flow of air into the EVAP system.

The purge valve is the most important piece since this valve opens with the help of a 12v supply. In general, these valves are solenoids that open and close once the right pressure is met. But later on, we are going to further elaborate on them.

The important thing, for now, is to learn more about the P0496 Chevy. And that’s what we are going to cover in the following chapter in detail.

Evaporative Emission System High Purge Flow

Now let’s move on and learn more about the P0469 Chevy and see more about the code. As with every code, the P0469 has a definition.

The definition of this code is “P0496 Evaporative Emission System High Purge Flow”. So, what does this means in the first place?

Well, as we noted previously, this code is connected to your EVAP system. There are a number of different codes for this EVAP system that can mean different things.

But in our case, the P0469 code means that there is a high flow of gases from the purge valve into the intake manifold of the car.

In other words, there is a purge of gases in situations when this shouldn’t be the case. So, the computer of your car has trouble adjusting the air-to-fuel ratio.

And these problems with the air-to-fuel ratio can be serious and need to be handled quickly before this problem creates more problems in your car. And we will get to that in a bit.

What is worth noting when you get this P0496 Chevy code is that you will also probably get other codes that are associated with your EVAP system. And more about them, we will also cover in a bit when we will discuss the symptoms. Now let’s move on and learn if the P0496 code is a serious problem or not.

Is The P0496 Chevy Serious

So, we learned what is the P0469 Chevy, now let’s take a look at how serious is this problem on your car. Should you be worried because of it or not?

Well, the code is not that serious because it doesn’t create a lot of symptoms. But this doesn’t mean that you should keep driving like this for a long period of time.

This is the case because some of the components on your car can get damaged if they are exposed to this type of engine work in the long run.

So, components like your O2 sensor and catalytic converter can take the toll and fail because of this type of engine work. In addition to this, there will be also a big drop in fuel economy and this could significantly hurt your wallet.

So, beware of these things before you think twice about leaving the problem unsolved. But how to solve the problem? What are the causes for the P0496 Chevy? Let’s elaborate more about them in the next chapters.

P0496 Chevy Causes

So, we covered the P0496 code meaning and learned what this code means. As well as whether it is a serious problem or not.

Now let’s take some time and learn more about the causes of the P0496 Chevy and learn about what can cause this problem in your car. So, without further ado, let’s dive into the probable causes.

P0496 Chevy Causes #1: Bad Purge Valve

The first and frankly, the most common cause for the P0496 Chevy is the bad purge valve. So, what is the purge valve?

Well, as we noted, this valve serves the special purpose of purging the gas fumes that have been collected in the charcoal canister. In short, this is what makes driving with a bad purge valve a bad idea.

This purge valve is constantly supplied with 12v power and whenever there is enough vacuum, the valve will activate and will purge the exhaust gases inside of the intake manifold. Now let’s move on to the next probable cause.

P0496 Chevy Causes #2: Bad Vent Valve

Now let’s move on to the second cause for the P0496 Chevy code. And this cause is the bad vent valve. So, what is a vent valve?

Well, the vent valve is a similar component to the purge valve. The function of this component is to vent the system. In other words, to prevent the pressure of vacuum buildup inside of the gas tank in case the purge valve doesn’t work. So, the vent valve is normally open, while the purge valve is normally closed.

And if this vent valve does not work, it will be constantly open, which is not a good thing and will cause a problem like in our case with the P0496 Chevy.

P0496 Chevy Causes #3: Leaking EVAP Hose

Next on our list of P0496 Chevy symptoms is the problem with the EVAP hose. This EVAP system has a lot of hoses that go through the car.

And unfortunately, they can crack and leak. Mainly because these hoses are made out of rubber. And rubber becomes really brittle as the car age.

So, I would recommend not touching them unless you want to damage them and trigger EVAP codes on your vehicle.

But they can also fail and cause problems such as these. This is why we would recommend that you check the hoses in the process before you make a conclusion. A leak test with a smoke machine is often the way to go to tackle leaky lines. Now let’s move on to the next cause for the P0496 Chevy.

P0496 Chevy Causes #4: Leaking Charcoal Canister

The next probable cause for the P0496 Chevy that we are going to cover is the leaking charcoal canister.

As we noted, in this EVAP system there is a charcoal canister that collects these gases and turns them into something less toxic.

This canister is made out of plastic and as we all know, plastic breaks. So, this component can easily trigger a code like the P0496 Chevy on your car. This is another really important component to check out and diagnose the symptoms of a bad charcoal canister.

P0496 Chevy Causes #5: Bad Gas Cap

The next and last probable cause for the P0496 code is the bad gas cap. So, why the gas cap is really important?

Well, this gas cap is basically your EVAP system control. If the gas cap does not have a proper seal, you will have a vacuum leak. This vacuum leak is going to leak these gases into the atmosphere and you definitely don’t want that.

If your car has a bad gas cap, you might notice other symptoms such as a P0442 code (as with the P0442 code Chevy Silverado) or P0455 code. That would also be accompanied by a gas cap check engine light, not to mention other error messages such as ‘check fuel cap’ on a Honda Accord.

You’ll naturally be concerned about what does ‘check fuel cap’ mean. Regardless, it’s probably a good sign that you need to consider a gas cap replacement.

So, consequently, codes like this or similar will be triggered. Some of the most common EVAP-related OBD diagnostics error codes that might appear include:

P0496 Symptoms

Now that we covered the P0496 Chevy causes, let’s move on and learn more about the common symptoms that often occur when you have this problem.

These are not strong symptoms. But in some cars, they will be present. So, you better watch out and see if you have one of these symptoms in your car. But what are the possible symptoms? Let’s elaborate more on them in the next chapters.

1. Check Engine Light

The first symptom when you have a P0496 code is the check engine light. And since you are here, you are probably aware of this. The check engine light will be triggered whenever you have problems with your EVAP.

P0496 Chevy

But what is worth noting is that other EVAP codes can be triggered as well. So, if there are other codes, you should also pay attention to them. Especially if one of them is concerned with the valves that we covered. This will help you pinpoint the problem much more quickly and come to a conclusion much sooner.

2. Trouble Starting

The next in our list of symptoms concerning the P0496 Chevy code is the difficulty starting the car. For example like in this case when you have a constant flow of unmetered air, starting the car can be problematic.

Mainly because you have a vacuum leak, there are gases from the gas tank constantly flowing into the engine. So, the computer will get really confused and not be able to adjust the air to fuel correctly at startup.

And this lean air-to-fuel mixture at the start will cause the car to be difficult to start. So, if you have some difficulties starting the engine, this could be the problem.

3. Car Runs Rich

The third symptom on our list of causes for the P0496 Chevy is the situation when the car is running rich (as opposed to your engine running lean). So, what is the situation when the car runs rich?

Well, this is a situation when your car’s air-to-fuel ratio is really messed up. And there is too much fuel and too little air.

All this will be triggered by the vacuum leak caused by the EVAP system. So, your engine will get unmetered air from the EVAP line and the computer will decide to pump in more fuel. More fuel means the mixture will be really rich after the car warms up and you will have a ton of problems.

4. Damaged Catalytic Converter

The next symptoms are the outcome of driving a code with a P0496 Chevy code in the long run. And one of these symptoms will be damage to the catalytic converter.

P0496 Chevy

The catalytic converter can get damaged if you run too much with a vacuum leak caused by the EVAP system.

It doesn’t matter if the fuel mixture is lean or rich, in the end, it will be damaging for your catalytic converter and you will regret that you drove like this. Since a catalytic converter can cost up to $2,000 for some models.

5. Damaged O2 sensor

The next symptom on our list that can be triggered as a consequence of running your car with the P0496 Chevy code for too long is the damaged O2 sensors.

There are two O2 sensors. One before the catalytic converter and one after the catalytic converter. These sensors are very sensitive to pollutants like silicone found in additives, and glycol solutions found in antifreeze, engine oil, as well as gasoline. All these compounds can foul the O2 sensors.

So, the outcome of this problem can be a very expensive sensor replacement job as well. So, be really aware of this since you don’t want to end up in this situation.

Diagnosing A P0496 Chevy Code

Now that we covered the causes and symptoms of the P0496 Chevy code. Let’s now move on and based on our knowledge, let’s try to solve the problem.

As we noted previously, this is a problem when you have a constant flow of gases into the intake of your engine. This means that the purge valve that is intended to stop them is leaking. There could be some of the other causes that we listed. But this is the most probable one.

So, what you want to do in this situation is to test the purge valve of your car. And for this, you want to remove it from the car. Usually, this purge valve is located in the engine bay. But it really depends on the carmaker where they will install the component. So, it really depends on the model.

You can test the purge valve in two ways. First, you can check if the valve opens and closes. For this, you will need a constant supply of 12v to activate the solenoid. If it activates, you will hear a little clicking sound.

But this doesn’t mean that the valve is good. It can also tend to leak. And to determine this, you will have to do a leak test. You can do this with a vacuum tester.

Just place the hose and pump a few times. If the PSI drops, it means that your purge valve is leaking. So, you will have to undertake a canister purge valve replacement and consider the cost to replace the purge valve. How the test is performed, you can check in the video above.

Driving With A Bad Purge Valve

We learned how to diagnose the P0496 Chevy, now let’s see how about driving with a bad purge valve (or if you notice the P0441 code or the P0441 Dodge code). Is this type of driving good for your car?

Well, even though you might not experience noticeable symptoms, there could be damage to the catalytic converter and O2 sensor in the long run.

P0496 Chevy: In Conclusion…

In this article, we have covered quite a bit when it comes to the P0496 Chevy code. First, we learned what this code is and its meaning.

Then we covered the causes, symptoms, as well as diagnostics. Usually, this code is triggered by a bad purge valve solenoid. So, in most cases, you will have to replace this solenoid on your car.

Frequently Asked Questions

Now let’s answer some frequently asked questions.

What Is EVAP

EVAP is the Evaporative Emission System. This is a system that basically collects the gas fumes from the gas tank and redirects them into the intake manifold of your car.

Can A Bad Purge Valve Cause Misfire

Yes, it definitely can. If the purge valve is open, it will cause unmetered air to enter the intake manifold and this unmetered air will cause misfires inside the cylinders. So, if you have a random misfire code, this could be one of the causes.

What Causes A Purge Valve To Go Bad

Usually, these components can go out just like that. They are solenoids that can fail internally and stop working. When the purge valve fails, usually there are no major factors to its failure. Just replace it and you will be good.

What Does Code P0496 Mean

This code means that you have a constant flow of gases into your intake manifold. In other words, the purge valve is leaky and loses some of the vacuum. So, this is the first component that you want to check to solve this problem.

How To Fix P0496 Code

You can fix this problem by replacing the purge valve on your car. This is the major cause of this type of code in your vehicle. You can also do a vacuum test on it. But there is highly likely that the valve is leaky and has to be replaced.

Will My Car Run Bad Without Vapor Canister

Yes, it will run badly and you will get the check engine light. Cars are designed with this system in mind and if you remove it, it will cause problems such as these. So, you will have to fix it if you want to get rid of the check engine light.

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